Identification of a sex pheromone component for Pennisetia marginata (Lepidoptera: Sesiidae)

Abstract

AbstractRaspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), is a native North American species and pest of many cane fruits. Using coupled gas chromatographic–electroantennographic detection analyses (GC-EAD) we identified candidate sex pheromone components in pheromone gland extracts and effluvia from calling females. Analysis of gland extracts on a Zebron-5 column revealed four components (A, B, C, and D) that elicited strong responses from male antennae. The two most EAD-active components A and B were hypothesised to be (3E,13Z)-octadecadienal [(3E,13Z)-18:Ald] and (3E,13Z)-octadecadienol [(3E,13Z)-18:OH], respectively. Their retention times on other GC columns matched those of authentic standards, thus supporting structural assignments. Synthetic (3E,13Z)-18:Ald, and its GC rearrangement product (2E,13Z)-octadecadienal [(2E,13Z)-18:Ald; component C], also induced antennal responses in GC-EAD analyses of female effluvia. Compounds D in pheromone gland extract, and E and F in female effluvia, elicited EAD responses but could not be identified. In field trapping experiments, (3E,13Z)-18:Ald was the only component that attracted male P. marginata when tested alone. Attractiveness of (3E,13Z)-18:Ald was reduced when combined in binary or ternary blends with any of the other identified components, suggesting one or all may act as pheromone antagonists. In Aldergrove, British Columbia, Canada, peak diel attraction of male P. marginata to (3E,13Z)-18:Ald occurred between 16:00 and 18:00 hours Pacific Daylight Time, at temperatures of 21–23°C, on 30 August 2010, 3 September 2010, and 13 September 2010. We conclude that (3E,13Z)-18:Ald is the major pheromone component of P. marginata.